Elastic linkage having detachable links designed for quick assembly



H. KNOOP May 30, 1961 ELASTIC LINKAGE HAVING DETACHABLE LINKS DESIGNED FOR QUICK ASSEMBLY Filed. Feb. 29, 1956 my. 7

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United States Patent ELASTIC LINKAGE HAVING DETACHABLE LINKS DESIGNED FOR QUICK ASSEMBLY Hendrikus Knoop, Utrecht, Netherlands, assignor to Rodi & Wienenberger, Aktiengesellschaft, Baden, Germany Filed Feb. 29, 1956, Ser. No. 568,649

Claims priority, application Netherlands Mar. 1, 1955 8 Claims. (Cl. 59-79) expand, and which are mounted between the transverse walls of the individual sleevelike links and parts of inter- ,mediate link elements which connect two adjacent sleeve like links and extend into the same.

Prior to this invention, link chains or bracelets of the 1 type as above described have already been known in which the intermediate link elements were designed to ,iorm U-shaped connecting members, the two arms of which engaged into the cross-sectional openings of adjacent links which were provided at the longitudinal edges of the chain or bracelet. The arms of the U-shaped connecting members then either acted upon small inserted .leaf springs or they themselves were designed to form springs.

In order to prevent these connecting members, which were inserted from both longitudinal edges of the :bracelet into the openings in the sleevelike links, from .falling out, either two opposite members were combined with each other to form a ring or they were secured in the links in such a manner that the ends of the arms of these connecting members snap under spring action into suitable detents or the like. In either case, however, the connecting members could not be subsequently removed, oronly by means of special tools, if it was necessary to increase or reduce the normal length of the chain or bracelet. If the connecting members were covered or secured by bent-over lugs projecting from the upper walls of the sleeve links, such lugs had to be unbent and could then hardly ever be bent back without affecting the appearance of the bracelet. In such bending they would often even break off entirely. Also, if such a bracelet was twisted or bent in a direction transverse to the direction of expansion thereof, the bent-over lugs easily became unbent by the U-shaped connecting members underneath so that the bracelet likewise depreciated in value and appearance.

The known link chains of bracelets of this type have the further disadvantage that, when the bracelet is expanded, unsightly gaps are formed between the individual sleeve links which ruins the appearance of a continuous unitary band. In order to overcome this disadvantage, elastic link chains or bracelets have previously been designed in which two superimposed layers of sleeve links were provided which were staggered relative to each other to the extent of one-half of the width of a sleeve link. However, such two-layer link designs according to previous proposals had the great disadvantage that the thick- 9 ice ness of the bracelet became too large, thus giving it a heavy, clumsy appearance.

it is an object of the present invention to provide an: expansion link chain or bracelet which is considerably; thinner than the previous two-layer link designs men-- tioned above, and in which, moreover, the gaps which form between the individual sleeve links when the bracelet. is extended will be covered so as to retain the continuous, unitary appearance of the bracelet.

Another object of the present invention is to provide a bracelet of the type as described in which the connect-' easily to another sleeve link after a few links have been added or removed.

A further object of the invention is to provide such a" bracelet as described in which the connecting members between adjacent sleeve links may, on the other hand, not become unintentionally unhooked or loosened.

Another object of the invention is to provide a bracelet which does not have the sharp edges which were prevalent in previous bracelets of this general type but in which the edges are well-rounded and smooth on all sides.

A further object of the invention is the provision of a link chain or bracelet which gives as much as possible the appearance of a continuous unitary band, regard less of whether the bracelet is extended or contracted.

Still another and very important object of the invention consists in the provision of an expansion bracelet, the individual parts of which are designed so as to be made and assembled very easily and at at low expense, and to be efiiciently mass-produced entirely by automatic machinery,

A feature of the present invention for carrying out the above-mentioned objects consists in the provision of a link chain or bracelet of the general type as described which consists of sleevelike links, subsequently referred to as sleeves, and intermediate members which con nect the adjacent sleeves and are provided vw'th small plate springs therein which act, and may be flattened, in the direction in which the bracelet expands. The new bracelet is particularly distinguished from those previously known by the fact that one of the two outer walls of each individual sleeve, i.e. those walls which connect the side walls thereof, is provided with a slot which extends transverse to the direction in which the bracelet expands and permits the insertion of those parts of the intermediate connecting members which engage into the sleeves. Each of these connecting members is offset with respect to the sleeves to the extent of the width of onehalf sleeve, and is made in the shape of an open box, the bottom of which extends transverse to the length of the bracelet and closely engages with the outer walls of the two adjacent sleeves, while the side walls of these boxlike members engage into the sleeves and are of a height substantially corresponding to the inner height of the sleeves. These side walls are separated from the bottom plate of each connecting member by slots which extend along the entire length of the side walls, and in which the mentioned outer wall portions of the sleeves are able to slide while engaging with the bottom plate of the connecting members. According to the invention, these bottom plates may also be stamped so as to bulgeoutwardly like a trough so that the outer surface and particularly the edges thereof will be smoothly rounded.

Another feature of the invention consists in the fact that the ends of each boxlike connecting member are closed so as to form end walls. When the bracelet-is;

3 contracted, these end walls will then cover the open ends of the sleeves.

Another feature which is very important from the standpoint of manufacture is the fact that, as previously pointed out, the slots in the connecting member which separate the side walls from the bottom plate thereof extend over the entire length of the member from one end wall to the other, and that these side walls which engage into the sleeves may be discontinuous and interrupted by a gap. This, in turn, means that the boxlike shape of the connecting members does not have to be produced by rather expensive stamping operations but may be formed very accurately by less expensive punching and bending operations.

Another feature of the invention is designed to prevent the connecting members from becoming unintentionally unhooked from the sleeves. For this purpose, the inner width of the sleeves, as seen in the longitudinal direction of the bracelet, may be made more than twice as large as the inner height of the sleeves and the wall portions of the connecting members which engage into the sleeves. Thus, each connecting member may be turned so as to stand at a right angle to the sleeves so that these wall portions of the two adjacent connecting members will then lie next to each other and flatly against the inside of that outer wall of the sleeve which is opposed to the slotted wall thereof. Then, a little U-shaped inner casing may be slipped into the sleeve so that the central part of the bottom of this casing will cover the slot in the wall of the sleeve from the inside thereof. This U-shaped casing serves the additional purpose of housing a pair of inwardly bent leaf springs which are preferably mounted on the lateral walls of the U-shaped casing and are adapted to engage with the side walls of the sleeve, so that, after the two connecting members have been pivoted back to their normal position, the wall portions of the connecting members in the respective sleeve will engage with and be acted upon by the leaf springs. These leaf springs may either be secured to the lateral walls of the U-shaped casing or form an integral part thereof. This may be done, for example, by making these side walls higher, splitting them longitudinally from both ends and bending the upper portion sharply inwardly, and then bending the outer ends of these portions inwardly to form leaf springs.

Further objects, features, and advantages of the present invention will appear from the following detailed description thereof and from the accompanying drawings of one preferred embodiment of the invention, in which Fig. 1 shows a top view, partly in section, of a part of a bracelet according to the invention with the members on the left side being illustrated in contracted or released position, and the members on the right side in expanded position;

Fig. 2 shows a side view, partly in section, of a portion of the bracelet according to Fig. l in a contracted position but on a more highly enlarged scale;

Fig. 3 shows a similar side view of one sleeve member, but with its two adjacent connecting members placed vertically upright thereon;

Fig. 4 shows an enlarged perspective view of one boxshaped connecting member similar to Figs. 1 to 3;

Fig. 5 shows a top view of a U-shaped inner casing with a pair of leaf springs mounted in the center of its side walls similar to Figs. 1 and 2; while Fig. 6 shows a view similar to Fig. 5, but with the leaf springs mounted at both ends on the side Walls of the U-shaped inner casing.

Referring to the drawings, the new link chain or bracelet according to the invention consists of individual sleeve members 10 of substantially rectangular shape which are open at both ends and the side walls 11 of which are closely adjacent and in engagement with each other when the bracelet is in its released or contracted position. One of the outer walls 12 connecting the side 4 walls 11 is provided with a longitudinal slot 13 which extends transversely to the longitudinal direction of the bracelet and divides this outer wall 12 into two wall portions 12a and 12b. These sleeve members may be easily made from flat sheet material by simple punching and bending operations.

The intermediate members 20 as shown in Fig. 4, which connect the adjacent sleeve members 10 are substantially of a shape of an open box with end walls 21. The side walls 22a and 22b are preferably interrupted in the center by a gap. The bottom of the boxlike member 10 forms a plate 23 which is separated from the side walls 22a and 22b by slots 24 which extend along the entire length of the side walls and through end walls 21 so that bottom plate 23 is merely connected with the central portion of end walls 21. Such shape of the connecting members 20 may likewise be easily obtained by punching the same out of a flat piece of material and then bending it as described above and shown in Fig. 4.

For assembling the bracelet, the respective side walls 22a and 22b of adjacent pairs of connecting members 20 which face each other are inserted into one sleeve member 10 through its slot 13, and are then stood upright thereto, as shown in Fig. 3, so that the inner surfaces of side walls 22a and 22b will rest flatly side-by-side against the inside of the solid outer wall 12 opposite the slotted wall 12a, 1212. This, however, necessitates that the inner width of sleeves 10 is more than twice as large as the inner height thereof, and that the height of side walls 22a and 22b is smaller than the inner height of sleeve 10. Thereafter, a U-shaped casing 30, as shown particularly in Figs. 5 and 6, which is of a size so as to fit closely into the opening in sleeve 10, will be slipped into such opening so that its bottom 31 will cover slot 13 of sleeve 10 from the inside thereof. Each of the side walls 32 of the U-shaped inner casing 30 are bent toward each other so that, when connecting members 20 are pivoted back from the position shown in Fig. 3 to that shown in Figs. 1 and 2, springs 33 will resiliently engage with the insides of side walls 22a and 22b, respectively, of connecting members 20. Thus, if the bracelet is expanded in its longitudinal direction, springs 33 will gradually flatten out and tend to contract the bracelet. If the bracelet should be shortened or lengthened, it will therefore only be necessary to tilt an adjacent pair of connecting members 20 to the position shown in Fig. 3, whereupon the U-shaped spring casing 30 may be slipped out of the respective sleeve 10, and the connecting members 20 be then unhooked from sleeve 10 through its slot 13.

Springs 33 may be secured to side walls 32 of casing 30 at the center thereof, as shown in Fig. 5, or form an integral part of casing 30, in which event side walls 32 may be made higher and the excess part be slotted longitudinally from both ends and then sharply bent over inwardly, whereupon the loose portions are bent to form springs 33. However, as shown in Fig. 6, the outer ends of side walls 32 of the U-shaped casing 30 may also be provided with cars 34 which are bent inwardly so as to form pockets in which the ends of springs 33 are held and are slidable in longitudinal direction when the springs are flattened.

The height of side walls 22a and 22b corresponds to that inner height of sleeve 10 which remains after the U-shaped spring casing 30 has been inserted into the sleeve so that, when the bracelet is contracted, the end walls 21 of connecting members 20 will cover the open ends of sleeve 10. Consequently, the bracelet will be closed on all sides and have a continuous, unitary appearance.

Usually, the individual members 10, 20, and 30 of the bracelet will be assembled so that slot 13 in sleeve 10, which is covered from the inside by the central portion of the bottom -31 of the -U-shaped spring casing 30, will lie downwardly, so that bottom plate 23 of the boxshaped connecting member 20 closely engages with the outside of the wall portions 12a and 12b oftwo adjacent sleeves which extend through slots 24 to the inside of the sleeves. However, the individual parts may also be assembled so that the covered slots 13 will lie at the upper side of the bracelet. Sleeves 10 may also be turned completely around in the assembled condition in the manner as shown in Fig. 3, so as to move the slotted side thereof from the lower side of the bracelet to the upper side, or vice versa. If the sleeves are turned so that slots 16 are on the upper side of the bracelet, special design effects may also be achieved, if, for example, the surface 31 of the U-shaped spring casing 30 which is partly viewable through slot 13 is made of a different color or provided with a different surface design than the outer surface of sleeve portions 12a and 12b. Also, slots 13, as well as the edges of bottom plates 23 when on the upper surface of the bracelet may be of various shapes or designs to improve and vary the appearance of the bracelet in accordance with the difierent tastes of different purchasers. Thus, for example, Fig. 1 shows at the right side the slot 13 placed at an inclined angle to the side walls 11 thereof.

Since bottom plates 23 of connecting members 20 are staggered relative to sleeves 10 to the extent of one-half of the width of a sleeve and closely engage with the lower edges of side wall portions 12a and 12b of connecting members 20, they completely bridge the gaps between the side Walls 11 of adjacent sleeves when the bracelet is expanded, so that even in such extended condition the bracelet will have the appearance of a continuous unitary hand. If desired, the bottom plates 23 may also be shaped so as to bulge or curve outwardly both for decorative purposes and also in order to round off the adjacent outer edges of the individual plates 23, as well as the outer edges of the entire bracelet.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim is:

1. An elastic chain comprising, in combination, a row of hollow link members open at the ends thereof, each link member having a first slot connecting said open ends thereof; a plurality of connecting members, each connecting member having a pair of side walls, a bottom wall and a pair of end walls connecting said bottom wall and said side walls, each connecting member having a pair of second slots respectively located between one of said side walls and said bottom wall, each of said second slots extending into said side walls and said bottom wall whereby said side walls are spaced fromgid bottom wall both transversely and vertically a distance greater than the thickness of said walls, the side walls of each connecting member being respectively located in two adjacent link members, said adjacent link members passing through said second slots of the respective connecting member, said end walls of said connecting members covering said open ends of said link members; and means located in each link member including a cover member covering said first slots thereof and a resilient means secured to said cover member, said cover member abutting against the inner surface of said link member and said resilient means abutting against at least one side wall of the two connecting members associated with the respective link member.

2. An elastic chain comprising, in combination, a row of hollow link members open at the ends thereof, each link member having a first slot connecting said open ends thereof; a plurality of connecting members, each connecting member having a pair of side walls, a bottom wall and a pair of end walls connecting said bottom wall and said side walls, each connecting member having a pair of second slots respectively located between one of said side walls and said bottom wall, each of said second slots extending into said side Walls and said bottom wall whereby said side walls are spaced from said bottom wall both transversely and vertically a distance greater than the thickness of'said walls; the side walls of each connecting member being respectively located in two adjacent link members, said adjacent link members passing through said second slots of the respective connecting members, said end walls of said connecting members covering said open ends of said link members; one outer surface of each link member in sliding arrangement with the inner side of a portion of the bottom of the respective connecting member; means located in each link member including a cover member covering said first slot thereof and abutting against the inner surface of said link member so as to be slidable in a direction transverse to the longitudinal extension of the link chain; a resilient means secured to said cover member, said resilient means abutting against at least one side wall of the two connecting members associated with the respective link members.

3. An elastic chain comprising, in combination, a row of hollow link members open at the ends thereof, each link member having a first slot connecting said open ends thereof; a plurality of connecting members, each connecting member having a pair of side walls, a bottom wall and a pair of end Walls connecting said bottom wall and said side walls, each connecting member having a pair of second slots respectively located between one of said side walls and said bottom wall, each of said second slots extending into said side walls and said bottom wall whereby said side walls are spaced from said bottom wall both transversely and vertically a distance greater than the thickness of said walls; the side walls of each connecting member being respectively located in to adjacent link members, said adjacent link members passing through said second slots of the respective connecting members, said end walls of said connecting members covering said open ends of said link members; one outer surface of each link member in sliding arrangement with the inner side of a portion of the bottom of the respective connecting member; means located in each link member including a U-shaped cover member having two legs and a crosspiece, said cross-piece portion covering said first slot of the link member and abutting against the inner surface thereof so as to be slidable in a direction transverse to the longitudinal extension of the link chain; a resilient means secured to said cover member between the legs thereof, said resilient means abutting against at least one side wall of the two connecting members associated with the respective link members.

4. A link chain as set forth in claim 1 wherein each of said connecting members is formed with two further slots, each further slot located in the center portion of one of said side walls and opening into the respective second slot whereby said connecting members can be produced by stamping and bending operations.

5. An elastic chain comprising, in combination, a row of hollow link members of substantially rectangular crosssection having opposite parallel side walls and opposite parallel outer walls defining a pair of open ends in each link member, each link member having a first slot in one of said outer walls connecting said open ends thereof; a plurality of connecting members, each connecting member having a pair of parallel opposite side walls, a bottom wall and a pair of end walls connecting said bottom wall and said side walls, each connecting member having a pair of second slots respectively located between one of said side walls and said bottom wall, each of said second slots extending into said side walls and said bottom wall whereby said side walls are spaced from said bottom wall both transversely and vertically a distance greater than the thickness of said walls; the side walls of each connect-- ing member being respectively located in two adjacent link members, said adjacent link members passing through said second slots of the respective connecting members, said end walls of said connecting members covering said open ends of said link members; one outer surface of each link member in sliding arrangement with the inner side of a portion of the bottom of the respective connecting member; means located in each link member including a cover member covering said first slot thereof and abutting against the inner surface of said link member so as to be slidable in a direction transverse to the longitudinal extension of the link chain; a resilient means secured to said cover member, said resilient means abutting against at least one side wall of the two connecting members associated with the respective link members.

6. An elastic chain comprising, in combination, a row of hollow link members of substantially rectangular crossseetion having opposite parallel side walls and opposite parallel outer walls defining a pair of open ends in each link member, each link member having a first slot in one of said outer walls connecting said open ends thereof; a plurality of connecting members, each connecting member having a pair of parallel opposite side walls, a bottom wall and a pair of end walls connecting said bottom wall and said side walls, each connecting member having a pair of second slots respectively located between one of said side walls and said bottom wall, each of said second slots extending into said side walls and said bottom wall whereby said side walls are spaced from said bottom wall both transversely and vertically a distance greater than the thickness of said walls; the side walls of each connecting member being respectively located in two adjacent link members, said adjacent link members passing through said second slots of the respective connecting members, said end walls of said connecting members covering said open ends of said link members; one outer surface of each link member in sliding arrangement with the inner side of a portion of the bottom of the respective connecting member; means located in each link member including a U-shaped cover member having two legs and a cross-piece, said cross-piece portion covering said first slot of the link member and abutting against the inner surface thereof so as to be slidable in a direction transverse to the longitudinal extension of the link chain; a resilient means secured to said cover member between the legs thereof, said resilient means abutting against at least one side wall of the two connecting members associated with the respective link members.

7. An elastic link chain as defined in claim 3, wherein the resilient means is secured to at least one leg of the U- sliaped member.

8. An elastic link chain as defined in claim 3, wherein the resilient means forms an integral part of said U- shaped member, at least one leg of said U-shaped member being slotted longitudinally from opposite ends, the wall portions above such slots being bent inwardly and toward the lower wall portions, and then being bent so as to form springs.

References Cited in the file of this patent UNITED STATES PATENTS 147,139 Kaufman Feb. 3, 1874 1,426,884 Levy Aug. 22, 1922 1,901,345 Carlson Mar. 14, 1933 2,430,776 Miller Nov. 11, 1947 2,753,681 Kupchick July 10, 1956 FORElGN PATENTS 824,076 France Feb. 1, 1938 918,184 France Jan. 31, 1947 2163.740 Switzerland Sept. 15, 1949 623,391 Great Britain May 17, 1949 299,000 Switzerland May 31, 1954 

